How to Troubleshoot the Air Conditioning in a 1999 Buick Century

Written by ross glyn
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to Troubleshoot the Air Conditioning in a 1999 Buick Century
Troubleshoot the AC in your 1999 Buick Century to find potential problem areas. (car heater vent image by robert mobley from

Keep the air conditioner running smoothly in your 1999 Buick Century by doing a little troubleshooting. Potential problems are simple to diagnose, whether it is a leaky AC hose or inadequate AC pressure. Run through a few simple steps before taking your vehicle in for service.

Skill level:

Things you need

  • AC compression test gauge

Show MoreHide


  1. 1

    Check the fuse box for any fuses that may have blown. The fuse box is located on the passenger side dash, just inside the door. Consult the schematic on the inside cover of the fuse box to find the fuse corresponding to the Century's AC system. If the metal wire inside the glass fuse is broken or damaged, replace it with another of the same amperage.

  2. 2

    Start the engine. Switch on the electric blower fan and AC to check if any of the AC controls are loose or resistant. If you do not hear or feel the fan turn on, this could indicate a blown fuse, or the fan itself might have malfunctioned. Replace the controls if they are damaged.

  3. 3

    Inspect the AC hoses for damage or leaks. Have the hoses replaced, if necessary. Check the AC compressor for any oily residue or leaks. Have the compressor replaced if you notice leaks.

  4. 4

    Start the engine. Check the two heater hoses protruding from the firewall under the hood One hose should be noticeably cooler than the other one. The hoses are roughly the thickness of a garden hose. The firewall is the metal partition between the passenger and engine compartments. If the hoses are both the same temperature, the valve control might be faulty. Have a mechanic replace the valve control.

  5. 5

    Check the AC system for adequate pressure. Turn the engine off and attach the AC pressure test gauge. Remove the black caps from the high and low service ports on the Buick Century's AC unit. Screw the blue hose to the low-side service port and the red hose to the high-side port.

    Check the reading on both the blue and red glass monitors. A normal reading should be between 50 and 80 PSI. Have a mechanic investigate further if the reading is out of this range, because it could indicate a leak in the system.

  6. 6

    Check to see that the magnetic clutch is operating correctly. Set the AC to the highest setting with the engine running. Open the bonnet and see if the magnetic clutch attached to the compressor engages. You will be able to see and hear it turn over. If the clutch does not spin, the system might be low on refrigerant. Have a mechanic refill the system.

  7. 7

    Check the drive belt to ensure it is tightly connected to the compressor. If the compressor is excessively loud, the unit may be failing. Have a mechanic replace the compressor. If you notice leakage around the compressor shaft seal, the seal also needs replacement.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.